1. Field of the Invention
The invention relates in general to a semiconductor package structure and an encapsulating module for molding the same, and more particularly to a semiconductor package structure whose sealant has a smooth surface and an encapsulating module for molding the same.
2. Description of the Related Art
Normally, the encapsulating mold is used during the process of packaging the substrate. The encapsulating mold has a cavity and a pressing surface. After the pressing surface contacts and presses the substrate, the cavity is filled with sealant. The sealant, having been cooled and solidified, is fixed on the substrate.
However, if there are radical changes in the shape of the interconnection between the pressing surface and the cavity of the encapsulating mold, many problems will arise. For example, the shape of the connection is a sharp corner. A number of disadvantages are exemplified below:
Firstly, when the encapsulating mold contacts and presses the substrate, what firstly contacts and presses the substrate are the pressing surface and the cavity. If the contact part has radical change in the appearance, such as a sharp corner. The sharp corner cuts and incurs tremendous stress on the substrate. The surface treatment layer and the metallic structure disposed on the substrate such as wires and pads are thus damaged. For example, Referring to FIG. 1, the semiconductor package of a generally known encapsulating mold having a sharp corner is shown. On the part of the encapsulating mold 200, the contact part between the pressing surface 202 and the cavity 204 is a sharp corner P1 with radical change in the appearance, wherein the sharp corner P1 makes the corresponding part of the substrate 206 to form a sharp corner P2. As the sharp corner P2 of the semiconductor package structure bears a high stress, the surface treatment layer (not illustrated), such as a solder mask, on the substrate 206 will be damaged or peeled off.
Secondly, if the contact part has a radical change in the appearance, such as a sharp corner, the soft surface treatment layer disposed on the substrate when pressed is likely to bulge and peel off the surface treatment layer.
Thirdly, in terms of the mold theory, during the process of cooling and solidification, hot spots are likely to be formed on the portion of the mold having a radical change in the shape, such as a sharp corner, is likely to have, hence shortening the lifespan of the mold.
Fourthly, the part of the mold on which hot spots are formed will affect the quality of the semiconductor package structure.